EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

 I just got into this fascinating hobby.  Just redid a couple of radios I grew up with - a Majestic 1941, and Philco Model14 - 1933, chassis only. Now working on a Philco 96, 1930.  I decided I needed a real radio and found a Scott 16 in an Acousticraft cabinet.  It's not in the greatest shape as there is a fair amount of chrome damage and it is missing a few parts.  The receiver, power supply and speaker are intact and fairly unmolested, but I need knobs, the large dial pointer and a replacement plastic dial cover.  Are there reproductions of these parts?  Or, in particular, does anyone have a pointer they might want to sell?  I guess I can live with non original knobs and I think I could vacuum form a new dial cover.  I couldn't find anything at Radio Daze.

This project will be on the back burner for awhile, especially as I research dealing with the rust areas in the chrome.  Not sure I want to completely strip the chassis and have it re-plated.  I guess it depends on what it's value might be completely restored.

I've done a little research on the 16 in the forum's archives.  I'm not really sure of what I've got. I don't know how popular the 16 was or how it performed compared to the other Scott models.  Any input would be appreciated.

Thanks!

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It's hard to believe that the tiny replacement caps are equivalent to the electrolytics that are in there! Modern caps sure have shrunk unless I'm missing some parameter that needs to be much greater than I have.  My replacement caps are supposed to have a pretty good ripple handling capability so I hope I'm good to go.

David C. Poland said:

Your repo knob mailed this morning.

Also about what I probably used - 47 MFD at 63 volts. 

Robert;

I have been in the electronics trade for some 40+ years now and the size of electrolytic caps indeed getting smaller, surface mount components are a lot worse in this respect.

Better materials and technology plays a big part, but I do agree that the size modern replacements can be a little worrying.

Mike

Yes, the size reduction since the 1930's is amazing. I leave the originals top side for show. Try Mother's Mag Polish on these old electrolytics. They can shine up almost like chrome, especially the ones Scott installed originally.

I mount modern version underneath on a terminal strip. Careful - some are not to chassis ground.

I pulled the contents of the 3 electrolytics, cleaned them out and installed the new caps inside.  since it would be hard to get a good ground from inside the can, I drilled a small hole on the ends of the caps near the treads.  the negative comes through the hole and I will be able to tie that to a good ground or the isolated negative ring connections. The positive comes through the rubber with the aluminum rod and is soldered to the original terminal. I cut the cap off right below the crimp and then glued them back on after mounting the new cap inside.  Mother's chrome and aluminum polish made them shine.  It's very difficult to see they were modified from the outside.  Under the chassis, you would see about a half inch of ground lead.

The 50 mfd was also cut open, the new cap mounted inside with the leads coming through holes I drilled in the plastic right next to the terminals.  The can was then glued together again.  Trying to keep things looking as original as possible.

Not sure what I'm going to do with the resistors.  They are not far off, so I may try to use them.  Or, I may try to mold something around new precision resistors and paint them like the originals.  That would be a lot of work, though.  I have re-stuffed the 2 .05 mfd caps with new film caps and sealed the ends with the original wax.  What are most of you guys doing with resistors?  Do you try to keep the underside looking original, or do just go ahead and replace the resistors with modern counterparts?

Robert;

Making dogbones is the way to go, once you have the mold it's good for at least half a dozen resistors or more,

plus it's really satisfying to see the chassis look as close to original as you can get.

Remember that the resistor tolerance was around 20% from new and you can get away with quite a lot with tubes, pay attention to the working voltage, if you swap resistors out be aware that a lot of then newer types are only rated to a couple of hundred volts maximum, making dogbones allows you to have several resistors in one, just up the wattage of your replacements because they will be in epoxy and will be derated,

not as bad as it sounds as a 1/2 watt dogbone is huge compared to today's components.

mike

Thanks Mike.  The resistors in the amp/power supply are typical molded carbon, only larger than the molded resistors of the 60's  and later.  There are no dogbones.  I haven't been under the tuner but I doubt they are there either.  Perhaps that makes the job easier.  I need to do a bit of investigation.  I've seen some of the work people have done with dogbones and it looks good.

Robert;

you could adapt the molding method to suit your resistors if you felt that way inclined, the joint seam would require a little cleaning up, quite easy with epoxy putty,

The main problem I found was matching the original colours,

all depends on how far you want to go with your restoration,

mike

I use high-temp silicone (red) to make my molds. It should last for hundreds of castings. It is also very expensive.

I'm rebuilding the PS/Amp for the Scott 16 and decided to replace the resistors/caps, but will save the old ones to make molds at a later date.

This radio was obviously worked on previously and I have a question about one wiring change that was made from what the schematic shows.  Pin 1 of the speaker plug, which feeds the center tap of the output TR, should go to the output of the rectifier before the filter choke, according to the schematic.  Pin 1 on my speaker plug was wired to the filter cap after the choke.  Was this a documented change from Scott, a wiring error by a previous service tech, or done to lower the voltage on the output tubes?  I rewired it according to the schematics, assuming Scott had it right in the first place.

Also interesting to note that the grid and screen grid are switched around on one of the 6V6's is in the schematic.

Yes -pin one of the speaker socket should be wired ahead of the first filter choke, not after.  Same as the 19 tube Phantom and the 14 tube Scott Masterpiece - which use the same Scott speaker. I checked a Sixteen amp on the shelf, and it is wired as per diagram.  

Reversing the screen and grid wires on a 6V6 sounds serious. Are you sure? the 2 sockets are oriented differently. Count the socket lugs carefully.  The screen lead wire is high voltage. Don't know what the impact would be on that 6V6 - distortion? inoperative? reduced output?

The tube is wired correctly, the Rider schematic is wrong.  if it were wired the way it is in the schematic, I'm afraid the consequences would be dramatic!  I just pointed it out in case anyone tries to wire the amp as per the schematic.  Bad things would happen.

David C. Poland said:

Yes -pin one of the speaker socket should be wired ahead of the first filter choke, not after.  Same as the 19 tube Phantom and the 14 tube Scott Masterpiece - which use the same Scott speaker. I checked a Sixteen amp on the shelf, and it is wired as per diagram.  

Reversing the screen and grid wires on a 6V6 sounds serious. Are you sure? the 2 sockets are oriented differently. Count the socket lugs carefully.  The screen lead wire is high voltage. Don't know what the impact would be on that 6V6 - distortion? inoperative? reduced output?

Here's the amp/ps chassis mostly finished.  The aluminum transformer cover has not been re-chromed.  I'll wait with that till I find a safe place to do it.  I didn't have enough black cloth covered wire for the switch so,for now anyway, I used power cord.

Oops!  The pics are too big.  Post them later.

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